Yes, PC will have multiples of 3.
*as we considered the system as byte addressable, each instruction contains 3 bytes, so PC will increment by 3.
But, for this reason we can't just say that the answer would be multiple of 3. This might not be true all the time.
Here it worked because the starting address is multiple of 3. (300+answer) should be multiple of 3.
What if the starting address is not a multiple of 3.
In that case, we must subtract the starting address from all the options, the result which is multiple of 3 would be the answer.
So, (Option - starting_address) must be multiple of 3.
(600 - 300) = 300, is a multiple of 3.
# almost all the given answers are correct, but mine is an extension, where the starting address is not a multiple of 3.